Investigating electrical and dielectric characteristics of sodium chloride-based biodegradable polymer blend electrolytes for sustainable energy storage technology

This work explores green chemistry and the development of sustainable energy storage devices using non-toxic materials. In the fabrication process of electrodes activated carbon materials were used to create symmetrical electrodes. A solid polymer electrolyte (SPE) system is then formed through solution casting, utilizing chitosan (CHSN) and poly(2-ethyl-2-oxazoline) (POZ) as the polymer hosts to facilitate ionic transport with sodium chloride (NaCl) with the aid of plasticizer. Notably, the CSOZN5 system exhibits a relatively high conductivity of 3.59 × 10⁻⁴ S cm⁻¹. The non-Debye relaxation is indicated by the depressed semicircle, with a diameter below the real-axis and the asymmetry-broadness of tanδ. The electric and dielectric characteristics show similar trends with plasticizer concentration, with the highest dielectric constant recorded for the best ion-conducting sample. The electric modulus loss peak shift toward higher frequency indicated enhancement in the ionic movement for high plasticized systems. Through transference number measurement (TNM), the contribution of ions to the overall conductivity is identified, with the best ion-conducting plasticized CHSN:POZ:NaCl film demonstrating potential stability reaching 2.6 V. The capacitive behavior of the constructed electric double-layer capacitor (EDLC) is analyzed using the cyclic voltammetry (CV) test, revealing a specific capacitance (Cspe) of 9.11 F/g at 20 mV/s, signifying the possibility of green energy storage technologies with environmentally friendly materials.